23 Replies Latest reply on Aug 27, 2014 2:49 PM by James Riddell

    Stamping FEA

    James Riddell

      I'm trying to model stamping of sheetmetal by setting up an assembly of anvil/die/material for something we already do and know (approximately) the forces involved.  I believe that my constraints are correct (force on top of anvil, uniaxial restraints at the edges of the material, etc.) and the materials are properly defined but it still fails to run.  Contact is set up between the material and die/anvil, meshing works fine.  I can't seem to find any tutorial that covers plastic/permanent deformation.  (Ran this in linear static just for fun but the results of stress is ridiculous.)  Thanks in advance.

        • Re: Stamping FEA
          Roland Schwarz

          Standard FEA is not a great tool for this job.  There are other programs specifically designed to do this.  Look at BlankWorks.

          • Re: Stamping FEA
            Shaun Densberger

            Stamping is pretty tricky to handle from a numerical standpoint. As others have mentioned, there are other non-FEA programs designed to calculate very specific aspects of stamping. However, if you really do need to simulate the stamping process for other reasons, then you'll need to look at a more robust FEA code (LS-DYNA for example).

            • Re: Stamping FEA
              Jared Conway

              Challenging sim. There is a tutorial on it but it is very simplified

               

              To attempt, you need sim prem, non linear analysis. Von Mises plasticity.

               

              Start simple and get comfortable with the method and then you can try your full model.

               

              But if you need the flat pattern, like others have said, there are better tools that take your model and flatten. Like blank works.

              • Re: Stamping FEA
                James Riddell

                I don't have the opportunity to install (or time to purchase) other software.  I do have the premium version of SW.

                 

                Any suggestions of how to set up the anvil deforming the metal down through a die then another die 'coins' the metal to make a flat pad at a prescribed location.  How do I set these up to 'move' through the plastic deformation of the metal?

                  • Re: Stamping FEA
                    Jerry Steiger

                    James,

                     

                    You should be able to set up your analysis so that the die parts move just like in real life. If parts move at different times you can set up the displacements to occur at different "times" in the analysis. So, for example, in the first step the two dies would move together to form the part and in the second step the second die would continue moving to coin the part.

                     

                    Having said that, and acknowledging that I am not very knowledgeable about SolidWorks Simulation, I doubt that you are going to have much luck getting this to run. The biggest problem is probably going to be that elements in areas that have a lot of deformation are going to change shape so much that they fail. I don't think that SW Sim Premium has element morphing, so you will only be able to simulate the first stages of the deformation.

                     

                    I also suspect that getting good estimates for the coefficient of friction between your part and the various faces of the die may be difficult due to the high pressures involved. It's possible that there may be interesting temperature effects as well.

                     

                    Jerry S.

                    • Re: Stamping FEA
                      Jared Conway

                      I don't know what you are asking but if you want to move something , apply a fixture and enter a nonzero number to move it.

                        • Re: Stamping FEA
                          James Riddell

                          Jared, I'm not 'moving' anything per se, it's just a draw of material (3mm) through a die with a backing die at the bottom to coin a flat surface.  I'm not familiar with what you are describing.  Both dies are grounded/fixed and the anvil is restrained to move only in the vertical.

                      • Re: Stamping FEA
                        Roy Dean

                        James,

                         

                        Have you gotten errors?   Or does the simulation run, but give you un-realistic results?

                         

                        After much trial, I eventually got some pretty good results for this type of simulation.    The big problems that I encountered were that at some points during "deformation", the workpiece reaches a singularity that solidworks doesn't know how to handle.   The error I would get is a partial solve, and something like "unable to solve past xxx time" or something like that.    The way I solved it was to put a trivial time based loading (like a couple of lbs) on the part just a short time prior to the singularity, which would "force" solidworks to continue the solve in the direction I needed it to go.    I hope this makes sense, I wish I could provide models for you to look at, but it's all proprietary.

                         

                        --Roy

                        • Re: Stamping FEA
                          James Riddell

                          Just to update everyone who has offered helpful advice, I haven't given up on doing this in SW but have (fairly easily) gotten it to run in Abaqus.  I'll be back.

                          • Re: Stamping FEA
                            James Riddell

                            I finally got access to the SW KB and this is about the only thing I found on the topic:

                            (Yeah, not entirely helpful...LOL)

                             

                            Solution

                             

                            Solution Id:

                             

                            S-042004

                            Product:

                             

                            Created:

                            9/15/2009

                            Updated:

                            8/22/2013

                            Area:

                            Simulation

                            Sub-Area:

                            Pre-Processing

                            Question:

                             

                            Does SolidWorks Simulation nonlinear module support analysis of metal stamping and cutting?

                             

                            Answer:

                             

                            No, it can not be done.

                             

                            Link: